All put togetherThe A50 and A70 look quite a bit more substantial with their fans attached. Clearance can be an issue for larger air towers, so I've taken some additional measurements that might help folks trying to decide whether either beast will interfere with their system's memory modules or motherboard heatsinks.

Corsair recommends that the coolers are oriented with the fans blowing air across the heatsink and toward a rear chassis exhaust vent. That puts the A50's fan above the DIMM slots on most motherboards, while the A70's fans hang over the DIMM slots on one side and power regulation circuitry (plus its associated heatsinks) on the other. If you mount the fans as high as possible, there's 1.4" (37 mm) of clearance between their bottom edges and the base of the CPU slug, leaving plenty of room for standard-height memory modules and taller VRM heatsinks.

The same set of mounting hardware is used to strap the A50 and A70 to any recent AMD or Intel socket. Installation is a tool-free process with AMD sockets, but you'll need to bust out a screwdriver to secure the H-shaped plate to the base for Intel CPUs. Pairing either cooler with an Intel socket requires a back plate whose installation will probably force you to remove the system's motherboard. Corsair's ownenclosures offer handy access panels to prevent users from having to pull apart their rigs to install CPU back plates, but that's hardly a common feature among even enthusiast-oriented cases.

Once you have the H-plate installed and the back plate in place, the A50 and A70 sandwich Intel sockets with the aid of four thumbscrews. If you're working in an enclosure that doesn't leave much room for your hands, a Phillips- or flat-head screwdriver can be used to turn the screws.

As one might expect, a tube of thermal compound is included with each cooler. There's enough for multiple applications using the pea-sized dollop of goop recommended by Corsair, and a couple of extra rubber fan posts are thrown in for good measure. I'd like to see at least one extra thumbscrew added to the box, as well.

By now, you're no doubt wondering how the A50 and A70 perform. The Benchmarking Sweatshop's collection of CPU coolers is pretty meager, but I do have a Thermalright Ultra-120 eXtreme with similar dimensions and a single 120-mm fan. To see how the Corsair heatsinks compared, I overclocked a Core i7-920 to 3.26GHz with a CPU voltage of 1.144V. My i7-920 is an engineering sample from the original Nehalem launch, so it runs a little hotespecially when hammered with an eight-way Prime95 load. CPU temperatures were monitored using Real Temp, and I noted the temperature of the hottest core (always core 0, incidentally) after 10 minutes at idle and under load. That was enough time for temperatures to stabilize with all three coolers.

The motherboard's BIOS was configured to run the CPU fan at full speed for each cooler. In addition, the A50 and A70 were tested with their in-line resistors capping fan speeds 1,600 RPM. All testing was conducted on an open test bench.

Only two degrees separate the coolers at idle, and the gaps barely widen under load. I'm a little surprised that there isn't more of a difference between the A50 and the A70 here, but it's nice to see that the slower fan speed doesn't greatly diminish the performance of either model.

That's particularly important because both Corsair coolers are much louder when their fans are spinning at the full 2,000 RPM. Noise levels were measured six inches from the top edge of the motherboard, but the difference between fan speeds was easily audible from several feet away. At that distance, it's very difficult to discern a difference between the A50 and the A70 with their fans set at 1,600 RPM.

To provide some context, I should point out that the Thermalright weighs 0.25 lbs (113 grams) more than the A70 and packs six heatpipes, none of which makes direct contact with the CPU. At about $60 online, the Ultra-120 is pricier than the Corsair coolers, too. The A70 costs $48, while the A50 can be had for only $40.

At those prices, the A50 and A70 look pretty competitive. Buy either throughNewegg before the end of the month, and you'll get a $15 mail-in rebate that sweetens the deal. The rebate check will likely take 6-8 weeks to arrive, if it does at all, but just think of how much you'll enjoy the anticipation.

Given the $8 difference between the A50 and A70, I'm torn on which I'd actually buy were I putting together a new system today. I suppose that would depend on how aggressively I was going to overclock. The A50 can certainly hold its own, but you really don't have to pay much more to step up to the A70, which can be made quieter by running only one of the two fans.

Honestly, though, I'm not sure I'd use either in my personal desktop. There's no doubt a lot to like: the Air Series is easy to install, features an excellent fan bracket, and lets users select one of two fan speeds. However, I'd much rather have a CPU fan with a four-pin header that's more cooperative with BIOS-level automatic fan speed controls, and part of me can't shake the suspicion that direct heatpipe contact might not be worth the crevices that line the base of each heatsink.